The Face of an Angel, directed by Michael Winterbottom, follows a troubled film-maker researching the murder trial in Italy. In 2009, Knox and her boyfriend Raffaele Sollecito were found guilty of killing British student Meredith Kercher, 21.

Her stabbed body was found in 2007 at the home she and Knox, now 26, shared. But the convictions were overturned in 2011 and a retrial is now under way in Florence.

Winterbottom’s plot focuses on the film-maker’s efforts to reconnect with his own daughter after seeing the murder victim largely forgotten by the media.

Rush star Daniel Bruhl plays the lead character, while Colin Firth is also rumoured to have some involvement.

(Image: NBC)

A source tells me: “It doesn’t look like Cara will be playing Foxy Knoxy but she will have a major role, as the director wants to focus on events surrounding the trial and the people whose lives have been affected by it.

“Getting Cara is a real coup for the film but is also brilliant for her career. It proves she’s an in-demand actress and will help to boost her career Stateside.

“She has been thinking about relocating there and, with big film offers coming in, it’s looking likely movies will soon be Cara’s main focus.”

Last month she signed with LA uber-agency William Morris, after a bidding war for her signature broke out in Tinseltown.

She already has three roles in the pipeline, including one in the film version of Martin Amis’ novel London Fields, alongside Billy Bob Thornton and Johnny Depp’s missus, Amber Heard.

Busy Cara also appeared in the adaptation of Tolstoy’s Anna Karenina and recently finished shooting Brit flick Kids in Love, about decadent rich youngsters.

Filming for The Face of an Angel starts in Siena and Rome next month, shortly after Cara wraps on London Fields.